NAME

Statistics::Descriptive::PDL::Weighted - A close to drop-in replacement for Statistics::Descriptive::Weighted using PDL as the back-end

VERSION

Version 0.04

SYNOPSIS

    use Statistics::Descriptive::PDL::Weighted;

    my $stats = Statistics::Descriptive::PDL::Weighted->new;
    $stats->add_data([1,2,3,4], [1,3,5,6]);  #  values then weights
    my $mean = $stat->mean;
    my $var  = $stat->variance;
    
    #  or you can add data using a hash ref
    my %data = (1 => 1, 2 => 3, 3 => 5, 4 => 6);
    $stats->add_data(\%data);
    
    #  if you want equal weights then you need to supply them yourself
    my $data = [1,2,3,4];
    $stats->add_data($data, [(1) x scalar @$data]);
    
    

DESCRIPTION

This module provides basic functions used in descriptive statistics using weighted values.

METHODS

new

Create a new statistics object. Takes no arguments.

add_data (\%data)

add_data ([1,2,3,4], [0.5,1,0.1,2)

Add data to the stats object. Appends to any existing data.

If a hash reference is passed then the keys are treated as the numeric data values, with the hash values the weights.

Unlike Statistics::Descriptive::PDL, you cannot pass a single flat array since odd things might happen if we convert it to a hash and the values are multidimensional.

Since the PDL::pdl function is used to process the data and weights you should be able to specify anything pdl accepts as valid.

An exception is raised the weights are <= 0, or are not the same size as the data.

sum_wts

Sum of the weights vector.

Statistical methods

Most of the methods should need no explanation here, except to note that the standard_deviation, skewness and kurtosis use the biased methods. This is because one cannot guarantee the data are sample counts. The same applies to the median and percentiles. The median uses a centre of mass calculation, and the percentiles using analogous approach. This is because the weights are not guaranteed to be integers and so there is no sense interpolating.

Use Statistics::Descriptive::PDL::SampleWeighted when your weights are counts and you need the unbiased methods.

The iqr is the inter-quartile range, calculated as the difference of the 75th and 25th percentiles.

geometric_mean

harmonic_mean

max

mean

median

min

mode

sample_range

standard_deviation

sum

variance

count

skewness

kurtosis

percentile (10)

percentile (45)

iqr

Not yet implemented, and possibly won't be.

Any of the trimmed functions, frequency functions and some others.

least_squares_fit

trimmed_mean

quantile

mindex

maxdex

AUTHOR

Shawn Laffan, <shawnlaffan at gmail.com>

BUGS

Please report any bugs or feature requests to https://github.com/shawnlaffan/Statistics-Descriptive-PDL/issues.

ACKNOWLEDGEMENTS

LICENSE AND COPYRIGHT

Copyright 2021 Shawn Laffan.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

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